There exists data having a sequential structure including data formed by a plurality of pages given consecutive numbers such as a book, and data formed by a plurality of pages given consecutive dates such as a scheduler. Such data having a sequential structure is implemented on a computer by the use of a queue or a linear list. It is more convenient to display consecutive pages of such data using as many windows on a display than to display them by using a single window as the plural pages can be referred to at once.
Further, a page turning operation for updating a plurality of pages displayed on the windows can be introduced so that the pages can be read ahead quickly. The page turning operation can be implemented by the use of a page turning button, a trackball, a flick operation, etc.
A system which has a plurality of windows and implements a page turning operation for updating the plural windows at the same time is disclosed, e.g., in a following document.
Japanese Laid-Open Patent Publication No. 2004-139399 discusses providing a displaying means having two display screens, for displaying an image of image data covering two facing pages on the display screens and for displaying images of following pages covering two facing pages on the display screens in series upon a page turning button being pushed.
Japanese Laid-Open Patent Publication No. WO2007/030682 discusses displaying two separate pages of an electronic document on a graphical user interface, and replacing a first pair of displayed pages of the electronic document with a second pair of displayed pages of the electronic document upon being selected by a page turning control.
Navigation Techniques for Dual-Display E-Book Readers, ACM CHI 2008, pp. 1779-1788 discusses an example for which not only two consecutive pages of data having a sequential structure are displayed on two screens, but a bookmarked page is displayed in one window and any page being displayed another window is compared with the bookmarked page.